Permalloy, Bar(Round bar, Flat bar),,E FORU

British Specs:，American Specs:MIL-N-14411 C ASTM A753，German Specs:

### **Permalloy - Round Bar & Flat Bar Product Overview** **Permalloy** is a nickel-iron soft magnetic alloy renowned for its extremely high magnetic permeability and low coercivity. The **Round Bar** and **Flat Bar** forms provide versatile stock material for machining components requiring superior soft magnetic characteristics and structural integrity in various electromagnetic applications. * **Common Names:** Permalloy Bar, High Permeability Nickel-Iron Alloy Bar * **Key Variants:** Permalloy 45 Bar, Permalloy 80 Bar --- #### **1. Chemical Composition** | Element | Permalloy 45 (%) | Permalloy 80 (%) | |---------|------------------|------------------| | **Nickel (Ni)** | 45-50 | 77-83 | | **Iron (Fe)** | Balance | Balance | | **Molybdenum (Mo)** | - | 0.5-2.0 | | **Copper (Cu)** | - | 3-5 | | **Manganese (Mn)** | 0.30-0.60 | 0.30-0.60 | | **Silicon (Si)** | 0.10-0.30 | 0.10-0.30 | | **Carbon (C)** | 0.02 max | 0.02 max | --- #### **2. Physical Properties** | Property | Permalloy 45 | Permalloy 80 | |----------|--------------|--------------| | **Density (g/cm³)** | 8.17 | 8.74 | | **Melting Point (°C)** | 1420 | 1450 | | **Curie Temperature (°C)** | 440 | 460 | | **Electrical Resistivity (μΩ·m)** | 0.45 | 0.55 | | **Thermal Conductivity (W/m·K)** | 18 | 16 | | **Thermal Expansion (μm/m·°C)** | 12.0 | 12.5 | --- #### **3. Magnetic Properties** | Property | Permalloy 45 | Permalloy 80 | |----------|--------------|--------------| | **Initial Permeability (μi)** | 2,500-4,000 | 20,000-50,000 | | **Maximum Permeability (μmax)** | 25,000-50,000 | 70,000-150,000 | | **Saturation Induction (T)** | 1.5-1.6 | 0.70-0.82 | | **Coercive Force (A/m)** | 8-16 | 1.2-2.4 | | **Residual Induction (T)** | 0.4-0.6 | 0.15-0.30 | --- #### **4. Mechanical Properties (Annealed Condition)** **Round Bar Properties:** * **Tensile Strength:** 480-550 MPa * **Yield Strength (0.2% Offset):** 250-320 MPa * **Elongation:** 35-45% in 2 inches * **Reduction of Area:** 50-65% * **Hardness:** 65-80 HRB * **Modulus of Elasticity:** 155 GPa **Flat Bar Properties:** * **Tensile Strength:** 470-540 MPa * **Yield Strength:** 240-310 MPa * **Elongation:** 30-40% in 2 inches * **Hardness:** 63-78 HRB --- #### **5. Product Specifications & Applications** **Round Bar Specifications:** * **Diameter Range:** 3.0 mm to 300 mm * **Diameter Tolerance:** ±0.1 mm (<25 mm), ±0.2% (>25 mm) * **Straightness:** ≤1 mm per meter * **Surface Finish:** 3.2 μm Ra standard, 1.6 μm Ra available **Flat Bar Specifications:** * **Thickness Range:** 3.0 mm to 100 mm * **Width Range:** 10 mm to 300 mm * **Thickness Tolerance:** ±0.15 mm (<10 mm), ±1.5% (>10 mm) * **Width Tolerance:** ±0.5 mm (<50 mm), ±1.0% (>50 mm) **Primary Applications:** **Round Bar Applications:** * **Magnetic Core Components:** Precision cores for instruments and transformers * **Sensor Elements:** Magnetic sensor components and flux concentrators * **Transformer Parts:** Core rods and structural magnetic elements * **Research Apparatus:** Components for physics research equipment * **Motor Components:** Magnetic circuit elements for specialized motors **Flat Bar Applications:** * **Magnetic Base Plates:** Foundation plates for sensitive instruments * **Transformer Yokes:** Magnetic flux carrying elements * **Structural Components:** Support elements requiring magnetic properties * **Fixture Bases:** Magnetic fixturing and tooling plates * **Shielding Elements:** Magnetic shielding plates and barriers --- #### **6. International Standards** | Standard Type | Standard Number | Title / Specification | |---------------|----------------|----------------------| | **ASTM** | **ASTM A753** | Standard Specification for Nickel-Iron Soft Magnetic Alloys | | **IEC** | **IEC 60404-8-6** | Metallic Magnetic Materials | | **MIL-SPEC** | **MIL-N-14411** | Nickel-Iron Magnetic Alloys | | **AMS** | **AMS 7701** | Aerospace Material Specification (Permalloy 45) | | **AMS** | **AMS 7702** | Aerospace Material Specification (Permalloy 80) | | **DIN** | **DIN 17745** | Nickel-Iron Alloys with Special Magnetic Properties | --- #### **7. Manufacturing & Processing** **Machining Characteristics:** * **Machinability Rating:** 25-30% (compared to 12114 steel) * **Recommended Tools:** Sharp carbide tools with positive rake angles * **Cutting Speeds:** 20-35 m/min for turning, 15-25 m/min for milling * **Feed Rates:** 0.08-0.25 mm/rev for turning, 0.05-0.15 mm/tooth for milling * **Coolant Requirements:** Essential for optimal tool life and surface finish **Critical Heat Treatment:** * **Final Annealing:** 1100-1150°C in pure dry hydrogen atmosphere * **Stress Relieving:** 400-500°C after heavy machining operations * **Cooling Rate:** Controlled cooling >100°C/hour through Curie point * **Atmosphere Control:** Essential for optimal magnetic properties **Special Handling Requirements:** * **Stress Avoidance:** Minimize mechanical stress after final anneal * **Proper Support:** Adequate support to prevent bending during storage * **Clean Handling:** Avoid contamination that could affect magnetic properties --- #### **8. Quality Assurance** * **Chemical Certification:** Mill certificate with heat analysis * **Dimensional Verification:** Statistical process control for size and straightness * **Magnetic Testing:** Permeability and coercive force measurement * **Mechanical Testing:** Tensile and hardness testing per ASTM standards * **Surface Quality:** Visual inspection and surface roughness measurement * **Ultrasonic Testing:** For internal quality assessment of large bars * **Traceability:** Full material traceability from melt to final product --- **Summary** **Permalloy Round Bar and Flat Bar** provide essential stock materials for manufacturing precision components requiring the highest levels of magnetic permeability and excellent soft magnetic characteristics. The availability of both Permalloy 45 (with higher saturation induction) and Permalloy 80 (with higher permeability) in round and flat bar forms offers design flexibility for various component geometries while maintaining superior magnetic performance. These materials are indispensable for sensitive instrumentation, aerospace systems, research equipment, and specialized industrial applications where both magnetic performance and structural integrity are critical. Compliance with **ASTM A753** and other international standards ensures consistent material performance and reliability. Proper heat treatment in hydrogen atmosphere, careful machining practices, and appropriate handling throughout the manufacturing process are essential to preserve the exceptional magnetic properties that define the Permalloy family of alloys.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 2549 gallon liquid totes Special package is available on request.